Bottom Line:
Based on the particular biochemical properties of the abnormal prion protein (PrPsc) associated with BSE, and particularly the increased degradation induced by proteinase K in the N terminal part of PrPsc, we have developed a rapid ELISA designed to distinguish BSE from other scrapie strains.This assay clearly discriminates experimental ovine BSE from other scrapie strains and was used to screen 260 transmissible spongiform encephalopathy (TSE)-infected small ruminant samples identified by the French active surveillance network (2002/2003).In this context, this test has helped to identify the first case of natural BSE in a goat and can be used to classify TSE isolates based on the proteinase K sensitivity of PrPsc.

ABSTRACTThe bovine spongiform encephalopathy (BSE) agent has been transmitted to humans, leading to variant Creutzfeldt-Jakob disease. Sheep and goats can be experimentally infected by BSE and have been potentially exposed to natural BSE; however, whether BSE can be transmitted to small ruminants is not known. Based on the particular biochemical properties of the abnormal prion protein (PrPsc) associated with BSE, and particularly the increased degradation induced by proteinase K in the N terminal part of PrPsc, we have developed a rapid ELISA designed to distinguish BSE from other scrapie strains. This assay clearly discriminates experimental ovine BSE from other scrapie strains and was used to screen 260 transmissible spongiform encephalopathy (TSE)-infected small ruminant samples identified by the French active surveillance network (2002/2003). In this context, this test has helped to identify the first case of natural BSE in a goat and can be used to classify TSE isolates based on the proteinase K sensitivity of PrPsc.

Mentions:
As shown in Figure 3, only 10 samples (3.8%) provided ratios compatible with experimental BSE (normalized ratio 0.7–1.3), and 28 provided ratios superior to experimental BSE in sheep (normalized ratio >1.3–10.5, Figure 3). Twenty-nine samples, as well as 4 of the 10 samples compatible with experimental BSE and 9 samples with low levels of PrPres, were previously identified as atypical scrapie (open bars, Figure 3). Among the samples that yielded ratios compatible with experimental BSE in sheep, 1 goat isolate, Ch636, was extensively studied because of its BSE-like profile in 3 different Western blot techniques (1). As shown in Figure 3, this sample had a normalized A/A′ratio close to 1, very similar to that for experimental goat BSE (Figure 4, panel A, Table 2). This result is confirmed by the migration pattern of the nonglycosylated band (Figure 4, panel B, lane 6), which appears very similar to that of experimental BSE in sheep (Figure 4, panel B, lane 4) and of experimental goat BSE (lane 5), and different from that of French scrapie goat isolates (lanes 7 and 8).

Mentions:
As shown in Figure 3, only 10 samples (3.8%) provided ratios compatible with experimental BSE (normalized ratio 0.7–1.3), and 28 provided ratios superior to experimental BSE in sheep (normalized ratio >1.3–10.5, Figure 3). Twenty-nine samples, as well as 4 of the 10 samples compatible with experimental BSE and 9 samples with low levels of PrPres, were previously identified as atypical scrapie (open bars, Figure 3). Among the samples that yielded ratios compatible with experimental BSE in sheep, 1 goat isolate, Ch636, was extensively studied because of its BSE-like profile in 3 different Western blot techniques (1). As shown in Figure 3, this sample had a normalized A/A′ratio close to 1, very similar to that for experimental goat BSE (Figure 4, panel A, Table 2). This result is confirmed by the migration pattern of the nonglycosylated band (Figure 4, panel B, lane 6), which appears very similar to that of experimental BSE in sheep (Figure 4, panel B, lane 4) and of experimental goat BSE (lane 5), and different from that of French scrapie goat isolates (lanes 7 and 8).

Bottom Line:
Based on the particular biochemical properties of the abnormal prion protein (PrPsc) associated with BSE, and particularly the increased degradation induced by proteinase K in the N terminal part of PrPsc, we have developed a rapid ELISA designed to distinguish BSE from other scrapie strains.This assay clearly discriminates experimental ovine BSE from other scrapie strains and was used to screen 260 transmissible spongiform encephalopathy (TSE)-infected small ruminant samples identified by the French active surveillance network (2002/2003).In this context, this test has helped to identify the first case of natural BSE in a goat and can be used to classify TSE isolates based on the proteinase K sensitivity of PrPsc.

ABSTRACTThe bovine spongiform encephalopathy (BSE) agent has been transmitted to humans, leading to variant Creutzfeldt-Jakob disease. Sheep and goats can be experimentally infected by BSE and have been potentially exposed to natural BSE; however, whether BSE can be transmitted to small ruminants is not known. Based on the particular biochemical properties of the abnormal prion protein (PrPsc) associated with BSE, and particularly the increased degradation induced by proteinase K in the N terminal part of PrPsc, we have developed a rapid ELISA designed to distinguish BSE from other scrapie strains. This assay clearly discriminates experimental ovine BSE from other scrapie strains and was used to screen 260 transmissible spongiform encephalopathy (TSE)-infected small ruminant samples identified by the French active surveillance network (2002/2003). In this context, this test has helped to identify the first case of natural BSE in a goat and can be used to classify TSE isolates based on the proteinase K sensitivity of PrPsc.